Marijuana use is becoming more accepted for medical and recreational purposes, but a new study suggests adults over 30 may want to think twice. Research from The University of Queensland found that continuing marijuana use past 30 is linked to lower success in areas like income, education, and happiness.

The study followed over 8,000 mothers and 2,000 children, analyzing drug use at ages 21 and 30. While younger users didn’t show major setbacks, the researchers noted that for those over 30, “lowered success rates” became apparent.

There are limitations, though. The study was conducted on Australian women, so it “may not represent other countries well.” It also used markers like homeownership and relationship status, which don’t necessarily reflect everyone’s idea of success.

Another issue is that the study didn’t track other drug use, admitting that findings could be influenced by “polydrug use generally rather than the specific use of cannabis.”